Square Wave Voltammetry (SWV)

Square Wave Voltammetry (SWW) is in fact a special version of Differential Pulse Voltammerty (DPV).

Differential Pulse Voltammerty is Square Wave Voltammetry when t pulse is equal t interval/2. The interval time is the inverse of the frequency (Freq):   t interval = 1/ Freq. As in DPV, the pulse amplitude is also normally in the range of 5 – 25 or 50 mV.

square wave voltammetry
Potential applied during Square Wave Voltammetry

Measuring Square Wave Voltammetry (SWV)

In trace analysis, it is important to apply a frequency with optimal values. As in DPV the optimal value must be found by varying the frequency.

SWV is sometimes used to measure the reaction rate of the electrode reaction.  In this case, a plot of the currents observed in the positive potential pulses are plotted next to the currents measured in the negative potential pulses (forward and reverse currents).

The shape of these curves shows how reversible or how fast the electrode reaction is.

typical square wave voltammetry plot
Typical SWV plot